By Mark Andrews

A study into the causes of severe equine asthma (sEA) has revealed associations with over 113 substances, including latex found in artificial surfaces.

Lead researcher Sam White found that natural rubber latex was among “the most surprising and significant” of several new allergens present in the dust horses breathe.

The study used advanced computing power to assess 400 potential allergens in over 130 sEA-affected and healthy horses, working with research groups in Switzerland, France, Canada, and USA.

The study revealed several previously suspected allergens, such as pollen, mold, and insect proteins, are likely involved in sEA, but the most surprising finding was the implication that natural rubber latex might also play a role. In fact, four of the five most significant allergens associated with sEA were latex proteins. The fifth was a protein from Aspergillus fumigatus, a common fungus previously linked with sEA. Until now, latex had not been tested due to limitations associated with classical allergen assessment methods.

White, now based in Nottingham Trent University’s School of Animal, Rural and Environmental Sciences, carried out the study for the Royal Agricultural University (RAU) and the University of Nottingham.

The research used mathematical modelling to allow diagnosis of sEA from a blood sample, avoiding the need for more invasive diagnostic techniques currently employed.

“The most significant and surprising allergens associated with sEA were from natural rubber latex,” he said. “Latex is historically associated with the equine environment in the form of artificial surfaces on arenas and racetracks.

“The high level of respirable dust associated with training on these surfaces has already been linked with chronic bronchitis, inflammation, and oxidative stress in riding instructors, and latex has long been associated with a variety of respiratory conditions in humans.

“These early results show it could be linked to respiratory problems in horses too, although it is too early to make a firm conclusion based on these data.” 

He added that further research is needed to establish the levels of latex horses are exposed to in their environment, and the effects it has on them.

White said the identification of new allergens would improve allergen avoidance and inform future diagnostic tests and therapies. 

For more details, see Antigen array for serological diagnosis and novel allergen identification in severe equine asthma.

Printed with permission of Mark Andrews, Equine Science Update.

Photo: Shutterstock/Dennis W Donahue